# Comma as decimal point leading to confusion [duplicate]

This question already has an answer here:

I'm writing a report in a language that uses decimal commas. In some cases that clashes with commas used for punctuation, causing hard to read text, e.g.:

for $x_i \in [-1,5, 1,5]$.

Is there a way to make this more readable?

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## marked as duplicate by krlmlr, dustin, mafp, Martin Schröder, XavierJul 28 '13 at 0:17

–  xport Jul 26 '11 at 17:51
Of course you aren't writing $ and $ for the brackets, are you? –  egreg Jul 26 '11 at 17:54
@egreg: Oops, no I'm not. –  htorque Jul 26 '11 at 17:58

If you're using the comma as decimal separator, then you should consider using the semi-colon for the interval separator, it will be more readable:

$x_i\in[-1{,}5;1{,}5]$


(Instead of typing 1{,}5, you can also use the icomma package as suggested by egreg or \num as suggested by Werner.)

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That was the first version I tried. Looks good on the screen but I didn't like it very much when printed. –  htorque Jul 26 '11 at 18:12
+1, semicolon should absolutely be used. Spacing is nice and all but even with proper spacing this is way too confusing otherwise. –  Konrad Rudolph Jul 26 '11 at 18:52
@htorque: in French you would also add a thin space \, before the semi-colon. To my eye, it improves even further the readability of the formula, but depending on the language you're using, it might be against the rules. –  Philippe Goutet Jul 26 '11 at 19:04
+1 also from me. A semicolon should be used indeed. –  Stephen Dec 25 '12 at 15:59
\usepackage{icomma}
...
for $x_{i}\in[-1,5, 1,5]$.


Notice the space after the comma where you want it to act as a punctuation symbol.

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Nice, definitely an improvement! Yet I think it still needs additional space between the elements (like suggested by Stephen). –  htorque Jul 26 '11 at 18:11

The siunitx package provides a general way of treating numbers and their decimal symbols. However, you have to explicitly encompass the numbers with \num{...}. For example:

\documentclass{article}
\usepackage[decimalsymbol=comma]{siunitx}
\begin{document}
This is a range $x_i \in [\num{-1,5},\num{1,5}]$.
\end{document}​​​​​​​​​​​​​​​​​​


would produce

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This has been replaced by output-decimal-marker in siunitx version 2. –  krlmlr Jul 27 '13 at 20:31

You could try \; or \, or ~ as space (instead of " "):

$x_i \in [-1,5,\;1\,1~1,5]$


and use a semicolon for the interval separator (as already suggested by Philippe Goutet).

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